Quote Originally Posted by Nathan289 View Post
1. Lack of zinc in oil... but I suspect there's more involved
2. Over adjusted rocker arms... added to the bad oil.
3. Plugged oil gallery that supplies oil to the lifters in cylinder 5.
#1) My engine builder used SAE 30 with ZDDP additive. I've been using Kendall GT1 Platinum 20-50 specifically because it has ZDDP.
#2) Have always seemed to have an issue with valve adjustment. No matter what I did, or how many times I did it over, I ended up with noisy lifters.... I wonder if I just had some bad lifters?
#3) My engine builder was particularly good at ensuring all galleries are clean. But... who knows.

Two possibilities Randy and I came up with is 1) inadequate break-in, and 2) too much valve spring pressure. I had ordered the "302" springs with dampers from Classic Inlines, but they sent the hell-for-bent compound springs, the strongest springs they sell... so we used 'em.